Thousands of people took to the streets of Stuttgart, Germany to protest a new curriculum set to emphasize sexual diversity. Several groups clashed with police resulting in at least 18 people sustaining injuries.

A mass rally called “Demo für alle” (Demonstration for everyone) was held on Stuttgart’s central Schillerplatz square on Sunday. According to police, about 4,500 people took part in the demonstration, which was organized by the conservative civic association “For Marriage and Family,” whose motto is “Stop gender ideology and sexualization of our children,” local media report.

Demonstrators were protesting the upcoming adoption of a new school curriculum that is expected to be approved by the regional government just before elections. A statement posted on the official site of the rally organizers says that the regional Culture and Education Minister intends to “surreptitiously” sign the document, which has provoked heated public discussion for the past two and a half years.

Meanwhile, the regional Culture and Education Ministry has argued that the public has taken part in the curriculum reform, and its signing is a mere formality, Die Welt reports.

The group that arranged the rally, which “stands for marriage and family… as well as against reeducation [of children] by organized lobby groups,” were protesting a new curriculum that puts special emphasis on “accepting” sexual diversity and sexual minorities.

“The people ‘Demo für alle’ protest against sexualization of children in schools… People from [LGBT] movements try to introduce their ideology and their idea… of acceptance of different sexual behavior into the curriculum. And a lot of parents are against this,” Dr. Norbert Neuhaus from the Foundation for Family Values told RT.

“It is a question of the parents’ right to decide on the education of their children,” he added.

During the rally, the organizers called on demonstrators not to vote for the Green and Left parties that make up the acting government in the forthcoming elections.

On the same day, a number of left-wing organizations staged several counter-rallies in Stuttgart, which were attended by “hundreds” of people, local media reported, citing police sources that would not reveal the exact number present. The counter-protesters shouted slogans such as “Our children will be like us,” and carried placards and banners reading, “Back to the Middle Ages? No, thank you!”

A regional women’s association, which accused “Demo für alle” of having a sexist ideology, had called on people to come out to protest the rally, stressing that everyone has the right to sexual self-determination.

Additionally, actors from the regional state theater and other artists staged a cultural festival in front of Stuttgart’s opera house to call for tolerance and openness. A huge rainbow banner bearing the word “diversity” was hung on the opera building for the event.

Earlier in the day, left-wing counter-protesters showered stones on three buses carrying opponents of the new curriculum to Stuttgart. Police detained suspects after the incident.

In the meantime, Rolf Steiner, an RT contributor at the scene, reported “heavy clashes” between police and left-wing protesters resulting in “many arrests.” Police first tried to disperse the leftist crowd, which attacked police officers in response. Clashes between the left- and the right-wingers also took place, he added. Several people were reportedly hospitalized.

The new “sexual diversity oriented” curriculum is part of the regional government’s action plan aimed at supporting diversity and tolerance, as well as at preventing discrimination based on sexual orientation.